To accurately control controlled object in a time variant system with a dead time such as a Czochralski method single crystal production device (CZ equipment). The dead time, the time constant, and the process gain value of a controlled object (CZ equipment) (200) are set. The process gain preset value has specified time variant characteristics. An output value y and its first-order and second-order time differentiated values are used as the state variable x of the controlled object (200). A nonlinear state predicting unit (206) predicts a state variable value x(t+Ld) at a future point in time after the dead time, based upon the current output value y, the dead time, the time constant, and the process gain preset value. A gain scheduled sliding mode control unit (212) performs a gain scheduled sliding mode control operation based upon the state variable value x(t+Ld) at the predicted future point in time, an output deviation z(t+Ld) at the future point in time, the time constant, and the set value of the process gain at the future point in time, to determine the manipulated variable uT of the controlled object (200).